Radiative baryonic B decays

We study the structure-dependent contributions to the radiative baryonic B decays of B→BB¯′γ in the standard model. We show that the decay branching ratios of Br(B→BB¯′γ) are O(10−7), which are larger than the estimated values of O(10−9) induced from inner bremsstrahlung effects of the corresponding two-body modes. In particular, we find that Br(B−→Λp¯γ) is around 1×10−6, which is close to the pole model estimation but smaller than the experimental measurement from Belle.